Effects of Thickness of Electrosprayed Spherical TiO2 Photoelectrodes on the Performance of Dye-Sensitized Solar Cells

Abstract

In a dye-sensitized solar cell (DSSC) consist of a TiO2 nanostructured photoelectrode, the other components are the electrolyte and the counter electrode. Dye molecules adsorbed onto the surface of the TiO2 photoelectrode provide electrons; thus, the photoelectrode determines the performance of the cell. TiO2 photoelectrodes for DSSCs can be fabricated using a number of techniques. Among the various techniques available, the electrospraying method has numerous advantages in that it uses a purely electric field to form the aggregate structure, allowing for independent control of the aggregation, size, and crystallinity of primary nanoparticles. In this study, we investigated the performances of DSSC photoelectrodes consisting of spherical TiO2 nanoparticles. The photoelectrodes were fabricated from a dispersion of TiO2 nanocrystals in ethyl alcohol by using the electrosprayin method, in which different amounts of the TiO2 dispersion were sprayed directly onto fluorine-doped tin oxide substrates. The highest energy conversion efficiency, which was 7.65% under light at AM1.5G, was obtained using a TiO2 electrode with a thickness of 9.5 μm. This was attributable to the high diffuse reflectance of the photoelectrode and the long lifetime of electrons in it. © 2016 by American Scientific Publishers.